Control for variable speed transmission



Aug. 30, 1966 E. P. BULLARD m CONTROL FOR VARIABLE SPEED TRANSMISSION 12 Sheets-Sheet 1 Original Filed Feb. 25, 1961 INPUT FIG INVENTOR. EDWARD P. BULLARD III Aug. 30, 1966 E. P. BULLARD Ill CONTROL FOR VARIABLE SPEED TRANSMISSION Original Filed Feb. 25,1961

l2 Sheets-Sheet 2 FIG.4

INVENTOR. EDWARD P. BULLARDIII Aug. 30, 1966 E. P. BULLARD m 3,269,231

CONTROL FOR VARIABLE SPEED TRANSMISSION Original Filed Feb. 23, 1961 12 Sheets-Sheet 3 P; A a 72 vm ///7// 1 FIG.5 A

A Z 4 48 VII INVENTOR.

P. BULLARDIDI ATTORNEY Aug. 30, 1966 E. P. BULLARD m 3,269,331

CONTROL FOR VARIABLE SPEED TRANSMISSION Original Filed Feb. 23, 1961 12 Sheets-Sheet IN V EN TOR.

5 P. BULLARD m ATT RNEY Aug. 30, 1966 E. P. BULLARD In CONTROL FOR VARIABLE SPEED TRANSMISSION 12 Sheets-Sheet 5 Original Filed Feb.

FIGJO INVENTOR. P. BULLARD JJI 30. 1966 E. P. BULLARD m 3,269,231

CONTROL FOR VARIABLE SPEED TRANSMISSION O g Filed Feb. 25, 1961 12 Sheets-Sheet 6 cnos H i] C ,3 3 /7 I, I6

I I I D2 i 1 A N m Ma /1m. ml/01 l7 l9 26 57 2| D a9 1 av 82/ 99 44 L 38 /Z H4 "3 1 I00 x 46 El 39 :2 M 25 3" R J18 37 36 1' 5 +02 wcs I04 48 us IOI I02 H? as :05 I06 I I 87 us 5% I i 1402 4 I I 15 21" J -28 I l9 N 26 2 gm 35 AI A2 29 fii =r";\33 FIG. l2 A INVENTOR.

EDWARD P. BULLARD III Aug. 30, 1966 E. P. BULLARD m 3,269,231

CONTROL FOR VARIABLE SPEED TRANSMISSION Original Filed Feb. 23, 1961 12 Sheets-Sheet '7 ATTORNEY Aug. 30, 1966 E. P. BULLARD m I 3,259,231

CONTROL FOR VARIABLE SPEED TRANSMISSION Griginal Filed Feb. 25, 1961 12 Sheets-Sheet 8 Q V" w E I j c] 'YJ I 61 2x41 41 a; .3 2 E58 2% to :2 x l i -J I l 0 INVENTOR.

2 W EDWARD P. BULLARDJII 1 LL 3 a g Aug. 30, 1966 E. P BULLARD m 3,

CONTROL FOR VARIABLE SPEED TRANSMISSION inal Filed Feb. 23, 1961 12. Sheets-Sheet 9 FEGJ4B FHE M INVENTOR. EDW P. BULLARD III ATTORNEY Aug. 30, 1966 E. P. BULLARD Ill CONTROL FOR VARIABLE SPEED TRANSMISSION 12 Sheets-Sheet 10 Original Filed Feb. 23, 1961 ZIB I I! II II m D Y mm M L R M 0 V U T N 10.. %A m w B Aug. 30, 1966 E. P. BULLARD m CONTROL FOR VARIABLE SPEED TRANSMISSION l2 Sheets-Sheet 11 Original Filed Feb. 23, 1961 [NV EN TOR.

QOIQDOOOD EDWARD P. BULLARD III ATTRNEY Aug. 30, 1966 E. P. BULLARD m 3,269,231

CONTROL FOR VARIABLE SPEED TRANSMISSION Original Filed Feb. 23, 1961 12 Sheets-Sheet 12 INVENTOR. EDWARD P. BULLARDm wgg ATTORNEY United States Patent M 3,269,231 CONTROL FQR VARIABLE SPEED TRANSMISSION Edward P. Bullard HI, 151 Cherry Lane, F airfield, Conn.

Original application Feb. 23, 1961, Ser. No. 91,207, now Patent No. 3,203,276, dated Aug. 31, 1965. .Divided and this application May 4, 1965, Ser. No. 453,079

6 Claims. (Cl. 82-2) The present invention relates to transmissions, and particularly to a control for producing a constant cutting speed as the tool of a machine tool is moved radially over a piece of work on a rotating work support.

This is a division of application Serial No. 91,207, filed February 23, 1961, now Patent No. 3,203,276, in the name of Edward P. Bullard III.

This invention is related to the invention shown, described and claimed in U.S. Patent No. 2,972,905, granted February 28, 1961, to E. P. Bullard III.

Conventional variable speed transmissions having a plurality of trains of gears that are rendered efllective by shifting clutches are capable of producing high torque at low speeds because as the effective gear ratio is varied to produce low speeds, the torque capabilities rise correspondingly. However, such transmissions are not steplessly variable and, therefore, are not suitable for many industrial installations.

The presently available steplessly variable speed transmissions that are capable of producing speeds from zero all have constant torque characteristics which, when the developed horsepower is plotted against speed, produce a straight line graph from Zero and having a predetermined slope. Such a transmission having a relatively slight slope can produce only low torque at low speed, and any substantial increase in torque can only be developed at a substantial increase in speed.

The cost to manufacture known steplessly variable speed transmissions having a substantially steep torque curve becomes increasingly great so that they have been limited economically to those having a relatively low torque at low speeds.

The principal object of this invention is to provide a steplessly variable speed transmission of economical construction and possessing relatively steep torque curve characteristics so that substantially high torque can be produced at relatively low speeds.

Another object of this invention is to provide a steplessly variable speed transmission having any desired speed range of substantially constant horsepower at any desired value.

Another object of the invention is to provide such a transmission in which the steplessly variable speed is effected with intermeshing gear trains and positive toothengaging clutches.

Still another object of the invention is to provide such a transmission in which a steplessly variable auxiliary speed transmission is combined with positive meshing, synchronous, clutch shifting transmission mechanism.

Still another object of the invention is to provide such a transmission in which the power that flows through the auxiliary transmission is only a small fraction of the total passing through the combined transmission.

Still another object of the invention is to provide a control for said transmission that is interlocked in a manner to prevent improper shifting of clutches within the transmission.

In one aspect of the invention, the transmission may comprise plural paths of power flow, each having an epicyclic gearing train therein. An epicyclic gearing train usually comprises at least a sun gear, a reaction gear and an arm supporting planet gears that mesh with the sun 3,269,231 Patented August 30, 1966 and reaction gears. Holding the reaction gear against rotation and rotating the sun gear causes the arm to rotate at base speed which depends upon the specific ratio of the gears forming the train and upon the speed of the sun gear. Rotating the reaction gear in the direction of the sun gear increases the arm speed above the base speed; and, rotating the reaction gear oppositely to the sun gear decreases the arm speed below the base speed.

In another aspect of the invention, the plural paths of power flow may be two, each leading to a single output shaft through suitable positive tooth-engaging clutches. The epicyclic gearing arrangement in each path may be effective alone for transmitting power to the output shaft through separate basic ranges of speed. In order to have the first basic range of speeds start at zero, the reaction gear of the epicyclic gearing in one of the paths is initially rotated in a direction opposite to its sun and at a speed such that its arm is stationary so that the speed of the output shaft is Zero. The speed of this reactor gear may be reduced in a stepless manner to zero and then increased in speed in the opposite direction to a predetermined value to thereby produce one of the basic ranges of speed.

The gearing leading to the reaction gear of the epicyclic gearing in the second path is such that when the reaction gear of the epicyclic gearing in the first path is at its top speed in the direction of its sun, the reaction gear of the second is rotating in a direction opposite to its sun and at a speed which, through suitable gearing, is rotating a clutch on the common output shaft at a speed that is synchronous with that of the clutch that drives the output shaft from the epicyclic gearing in the first path. Accordingly, the clutches on the output shaft may be shifted so that the epicyclic gearing of the second path alone drives the output shaft.' Then, by decreasing the speed of the reaction gear of the epicyclic gearing in the second path to zero and reversing its rotation and increasing its speed in the direction of rotation of its sun to a predetermined value, a second basic range of speeds of the output shaft is produced that continues uninterruptedly from the first basic range.

At this point, the reaction gear of the epicyclic gearing in the first path is now rotating opposite to its sun at a maximum speed. By changing the speed of rotation of its sun to a'value causing the first clutch on the output shaft to rotate at a synchronous speed with that of the second,these clutches can again be shifted so that the first epicyclic gearing now drives the output shaft alone. Then, by decreasing the speed'of the reaction gear of the epicyclic gearing in the first path to zero, reversing it and increasing it to its maximum value, a third basic range of' speeds is produced that continues uninterruptedly from the top of the second basic range.

Each of the three basic ranges of speed may be composed of four sub-ranges, two of which may be produced by another pair of epicyclic gearing arrangements and two of which may be produced by interposing reversing gearing between the first and second pairs of epicyclic gearing.

The second pair of epicyclic gearing arrangements may be operated as follows, only one at a time being effective as before. The reaction gear of one of the second pair of epicyclic gearing arrangements may be rotated at a speed, and in the direction of its sun, such that its output shaft rotates the reaction gear of the previously described epicyclic gearing in the first path of power flow in a direction opposite to its sun and at a speed such that its output is zero. The speed of the eifective reaction gear of the second pair of epicyclics is reduced to zero and increased in the opposite direction to its sun to a maximum speed. At this point the reaction gear of the other of the second pair of epicyclics is rotating at a maximum speed in the direction of its sun. Then, by rendering it effective by suitable clutches, decreasing the speed of this last reaction gear to zero and increasing it to maximum in the direction opposite to its sun causes its output and the effective reactor of the epicyclic within the first path of power flow to reduce in speed to zero so that the output therefrom, and the output shaft itself, have increased in speed from zero to base speed of the effective epicyclic gearing of the first pair. Since this latter reactor is now at zero speed, the reversing clutch can be shifted. Accordingly, since the reactor of the effective epicyclic of the second pair is now rotating at top speed in a direction opposite to its sun, decreasing its speed increases the output speed from its epicyclic from zero. Therefore, by retracing the steps of operation of the sec-nd pair of epicyclics, the speed of the effective reactor of the first pair of epicyclics increases to top speed in the direction of its sun, thereby increasing its output speed accordingly.

This action of the second pair of epicyclic gearing arrangements may be employed in the same manner with the other epicyclic gearing arrangement in the second path of power flow, as well as again with the first when its sun is rotated at a different rate of speed. From the foregoing, it is evident that twelve sub-ranges of speed can be produced in which each succeeding sub-range is a continuation from the top of the next preceding sub-range.

In another aspect of the invention, as the various clutches approach synchronous speed prior to shifting, they may be prevented from attaining exactly synchronous speed, so that in shifting clutches the teeth thereof will not land tooth-on-tooth.

In still another aspect of the invention, a control may be provided for actuating the steplessly variable device that is employed to rotate the reaction gears of the second pair of epicyclic gearing arrangements, and in the embodiment disclosed, this device may comprise a variable and constant displacement hydraulic unit within a closed circuit.

In still another aspect of the invention, hydraulic, positive acting, interlocking shuttles may be employed between the various clutches to insure their proper operation, and particularly the engagement of a clutch to carry the load prior to the disengagement of a clutch that is carrying the load.

In still another aspect of the invention, a servo system may be employed to automatically control the operation of the transmission, when it is employed to rotate a work supporting table of a lathe, to produce a constant cutting speed as a tool is moved radially across a piece of work on the table.

The above, other objects and novel features of the invention will become apparent from the following specification and accompanying drawings where are merely exemplary.

In the drawings:

FIGS. 1 to 12, inclusive, are schematic stretchout views of a transmission to which the principles of the invention have been applied, showing in section the flow of power therethrough for each of the twelve stages of the transmission;

FIG. 13 is a schematic hydraulic circuit diagram;

FIGS. 14, 14a, 14b, 15, a, 15b, 15c and 16 are sectional views of the interlocking mechanism in various positions;

FIG. 17 is a sectional view taken substantially along line 1717 of FIG. 16;

FIG. 18 is a detail of a clutch shifting piston and cylinder;

FIG. 19 is a schematic showing of certain of the control equipment;

FIG. is an electrical wiring diagram for the control shown in FIGS. 13 and 19;

FIG. 21 is a portion of a boring mill to which the transmission of the invention has been applied;

FIG. 22 is a view of a constant cutting speed control for the boring mill shown in FIG. 21;

FIG. 23 is a sectional view taken substantially along line 2323' of FIG. 22; and

FIGS. 24 and 25 are views of details of the control shown in FIGS. 22 and 23.

Referring to FIG. 1, the principles of the invention are shown as applied to a transmission, herein disclosed in a stretchout schematic form in which certain intermeshing gears are shown separated for clarity. Since a critical feature of this invention deals with the provision of a transmission having any desired predetermined range of speeds at substantially constant horsepower, the description will include a given set of values of gear ratios in order to clearly point out the theory of operation of the invention. It is, of course, understood that other ratios may be employed so long as they are applied in the same manner as those applied herein.

An input shaft A1 has fixed to it a pinion 10 having 21 teeth that mesh with a gear 11 having 63 teeth, which latter is fixed to a shaft C1, parallel to shaft A1. A gear 12 having 72 teeth integral with gear 11 meshes with a gear 13 having 40 teeth and which gear 13 is fixed to a shaft D1 also parallel to shaft A1. Sun gears 14 and 15, each having 40 teeth are fixed, respectively, to shafts C1 and D1 and they mesh with planet gears 16 and 17 each having 16 teeth. The planet gears 16 and 17 are journaled on pins supported by arms 18 and 19. Internal gears of reactors 20 and 21 each having 72 teeth, respectively, mesh with the planet gears 16 and 17, and reactor 20 is provided with an external gear 22 having 69 teeth which is in mesh with an idle gear 23 between it and an external gear 24 having teeth that is fixed to the reactor 21.

The arms 18 and 19, respectively, are integrally connected to shafts C2 and D2 that are coaxial with shafts C1 and D1, respectively, thereby completing the two planetary differentials which will be referred to hereinafter as the C and D planetaries. Slidable clutches M and N on shafts C2 and D2 are adapted, respectively, to connect and disconnect shafts C2 and D2 to shafts C3 and D3 through intermeshing gears 25 and 26 having 21 and 35 teeth, respectively. The shaft D3 is adapted to journal gears 27 and 28, each having 28 teeth, and between which integrally united clutches O and P are splined to shaft D3.

The gear 27 meshes with an external gear 29 having 5 6 teeth on a reactor 30, also referred to as AR, journaled on shaft 41. The reactor 30 includes an internal gear 31 having 60 teeth which meshes with planet gears 32 having 20 teeth journaled on pins fixed to an arm 33. A sun gear 34 having 20 teeth fixed to shaft A1 meshes with planet gears 32 to complete the planetary differential on shaft A1 which will be referred to as the A planetary.

The shaft A2 to which arm 33 is fixed has rigidly attached to it a gear 35 having 24 teeth which meshes with a gear 36 having 36 teeth. The gear 36 is journaled on an output shaft E1, and a clutch T splined to shaft E1 is adapted to connect and disconnect gear 36 to shaft E1.

The shaft C3 has a gear 37 with 28 teeth journaled on it. This gear 37 meshes with the external gear 29 of the reactor 30. A clutch Q splined to shaft C3 is adapted to connect and disconnect gear 37 to shaft C3. The gear 25 meshes with a gear 38 having 21 teeth that is fixed to a shaft L1 parallel to shaft C3. Shaft L1 also journals a gear 39 having 28 teeth that meshes with an external gear 40 having 56 teeth of a reactor 41. A clutch X is splined to shaft L1 and it is adapted to connect and disconnect gear 39 to it. The reactor 41 also includes an internal gear 42 having 60 teeth that meshes with planet gears 43 having 20 teeth, which latter are journaled on pins connected to an arm 44. A sun gear 45 having 20 teeth also meshes with the planet gears 43 and it is fixed to a shaft B1 that likewise is parallel to shaft L1. The arm 44 is integral with a shaft B2 axially aligned with shaft B1, thereby completing the planetary differential on shaft B1 which will be referred to as the B planetary. Shaft B2 journals a gear 46 having 38 teeth adapted to be connected to, and disconnected from, shaft B2 by a clutch U that is splined to shaft B2. The gear 46 is in mesh with a gear 46' having 19 teeth and which gear 46' is fixed to shaft E1. Also integrally attached to shaft B2 is a gear 47 having 12 teeth that meshes with a gear 48 having 45 teeth that is journaled on the output shaft E1 and adapted to be connected to, and disconnected from, shaft E1 by a clutch S that is splined to shaft E1.

The gear 28 meshes with the external gear 40 of the reactor 41 and is adapted to be connected to, and disconnected from, shaft D3 by a clutch P; While another gear 49 having 28 teeth also meshes with gear 40 of reactor 41 and gear 49 is adapted to be connected to, and disconnected from, shaft C3 by a clutch R.

The shaft B1 to which sun gear 45 is fixed also journals a gear 50 having 21 teeth that meshes with a gear 51 having teeth fixed to a shaft 52 parallel to shaft B1. A gear 53 having 21 teeth is also journaled on shaft B1 and it meshes with a gear 54 having teeth also fixed to shaft 52. A double-acting clutch LH is adapted alternatively to connect to and disconnect from shaft B1, the gears 50 and 53. Gear 53 meshes with gear 11 which is indicated by the dot and dash line in the stretchout schematic diagram.

A variable displacement hydraulic pump and motor unit 56 is drivingly connected to gear 12 through a gear 56' and it is in a closed circuit with a fixed displacement pump or motor unit 57 which latter is fixed to a shaft 58. A gear 59 having 14 teeth is driven from shaft 58 and it meshes with the external gear 24 of the reactor of the D planetary.

The variable displacement unit 56 may be of the type shown and described in Patent No. 1,931,969 granted to H. 'Ilhoma on October 24, 1933. This type of unit includes a control lever 60 that may be moved from its solid line position through a horizontal position to its dotted line position. In its number 1 position, the pump will rotate at full speed in one direction. In its horizontal or number 2 position, the pump idles and delivers or transmits no fluid. In its number 3 position, the pump will rotate at full speed in a direction opposite to that in which it rotated when lever 60 was in its number 1 position.

In order to clearly understand the principles of the invention, the flow of power with corresponding speeds and torques will be traced through the transmission.

Assume that the transmission is adapted to transmit HP. over a 13.521 constant horsepower range with a top speed of 1800 r.p.m. and with an input speed of 2100 r.p.m.

The range of output speeds at constant horsepower will be 1800 to 1800/13.5 or 1800 to 134. From 134 r.p.m. to zero, the HP. will decrease as a constant torque device. This constant torque will be HP 63,0OO 4=0 63,000 18,800 inch pounds 134 134. and represents the safe maximum torque that can be applied to the shaft E1.

With clutches L, N, X, S and Q engaged (FIG. 1), the lever 60 in the solid line number 1 position, and shaft A1 rotating at 2100 r.p.m. by a constant speed prime mover, not shown, power flows from shaft A1 through gears 10, 11, 12, 13 to the D planetary. It also flows through gears 10, 11, 53, 54, shaft 52, gears 51 and 50, clutch L to shaft B1. Rotation ofgear 12 causes pump 56 to deliver liquid under pressure at a predetermined pressure and maximum volume per revolution (with lever 60 in the number 1 position shown in FIG. 1) to pump 57 which supplies power through gears 59 and 24 to provide a reaction to effect the power flowing to shaft D1 to pass through the D planetary to the shaft D2. From shaft D2 the power is transmitted to the reactor 41 of pumping occurs.

and that of 72 D1=70O =126O r.p.m.

The base speed of a planetary differential is the speed of the arm with the reactor held against rotation. Rotation of the reactor in a direction corresponding to the direction of rotation of the sun gear increases the speed of rotation of the arm above base speed, while rotation of the reactor in a direction opposite to that of the sun gear decreases the speed of rotation of the arm below base 5 speed.

The speed of the various elements will be indicated in the following text and charts by prefixing the elements index with the letter S. Thus, the speed of elements D2, L1, BR, B2, E1, DR, B1, D1, C2, C1, CR, C3, AR, A2, A1 and D3 will be SDZ, SL1, SBR, S132, SE1, SDR, SB1, SDI, 8C2, 5C1, SCR, S03, SAR, SA2, SA1, and SD23.

Additionally, the torques on the various elements will be represented by the prefix T and the power in them will be represented by the prefix P. Thus the torque on the B reactor 41 will be represented as TBR and the power therein as PBR, and so on.

Let:

bs=arm r.p.m. at base speed.

sd=arn1 r.p.m. with sun gear fixed and such that reactor is rotating in same direction as sun if sun were released.

s0=arm r.p.m. with sun gear fixed and such that reactor is rotating opposite to sun if sun were released. 7

rds=arrn r.p.m. with reactor revolving in same direction as sun. ros=arm r.p.m. with reactor revolving oppositely to sun.

,(speed sun) d and so ,(speed reactor) rds=bs+sd r0s=bs-s0 where s and r are the number of teeth on the sun gear and reactor gear.

D planetary =233.3 r.p.m. (max) with lever 60 in its lower position.

Dbs= (1260)= 1260=450 r m 72+40 112 7 of SD2 with lever 60 central.

Dsd= (233 .3) =m X 233.3 150 r.p.m.

of SD2 with sun fixed and such that reactor is. rotating in same direction as sun 15 if the sun were released.

of SD2 with sun fixed and such that reactor is rotating oppositely to sun 15 if the sun were released.

Drds=SD2 with reactor of D planetary rotating in same direction as sun 15.

SD2=Dbs+Dsd=450+150=600 r.p.m. when lever 60 is Drs=SD2 with reactor of D planetary rotating oppositely to that of sun 15.

SD2=DbsDs0:450-150=:30O with lever 60 down.

with lever 60 in its down position. And, when lever 60 is in its up position, the C reactor rot-ates oppositely to sun 14 and its maximum speed is:

14 115 SCR=1917 Xm -388.9 r.p.m.

with lever 60 in its upper position.

of SCZ with lever 60 central.

Ds0= (233.3)=150 r.p.m.

72 Csd 388.9-250 r.p.m.

of SC2 with C reactor rotating in same direction as sun if sun were released.

72 Cs0- X388.9 250 r.p.m.

with C reactor rotating oppositely to sun 14 if sun were released. Crds=SC2 with reactor of C planetary rotating in same direction as sun 14. SC2=Cbs+Csd=250+250=500 r.p.m. with lever 60 in its lower position. Cr0s=SC2 with reactor of C planetary rotating oppositely to sun 14. SC2=Cbs-Cso=250-250=O r.p.m. with lever 60 in its upper position.

A planetary Referring to FIG. 8, it is noted that the reactor 30 of the A planetary rotates in the same direction as sun gear 34. Also, it is being driven through the D planetary. This is the only phase of operation of the transmission wherein this condition occurs. Although lever 60 is shown in its lower position in FIG. 8, and hence SD2 is minimum to begin with, when lever 60 has been moved to its upper position in this phase, the reactor 21 of the D planetary is rotating in the same direction as sun gear 15 and consequently SD2:600 r.p.m. maximum. The maximum speed of the reactor 30 of the A planetary when rotating in the same direction as sun 35 28 SAR-SD2(max.) X

Referring to FIG. 5, the reactor of the A planetary rotates in the opposite direction to sun gear 34. Also, it is driven through the D planetary. This is the only phase of operation of the transmission wherein this condition occurs.

With lever 60 in its upper position (FIG. 5), the D reactor rotates in the same direction as the sun gear 15 and, therefore, SD2=max.=600 r.p.m.; land, the maximum speed of the reactor of the A planetary when rotating oppositely to sun. 34 is 28 600 Xg -3OO r.p.m.

of SA2 when lever 60 is central.

r.p.m.

of SA2 with sun fixed but reactor rotating in same direction as sun gear 34 if sun gear were released.

Aso= (300) 300=225 r.p.m.

B planetary (1500 r.p.m. of B1) Referring to FIG. 4, the B reactor 41 is rotating in the same direct-ion as the sun gear 45 land is being driven through the D planetary. With lever 60 in its lowermost position (FIG. 4), the D reactor rotates oppositely to sun 15 and hence SD2 is minimum=300 r.p.m. (column 7). However, during phase 4, lever 60 is moved to its upper position where SD2 is rnaxinum1=600 r.p.lm. Therefore, the maximum speed of the reactor 41 of the B planetary in rotating in the same direction as the sun gear 45 is:

Referring to FIG. 1, the B reactor 41 is rotating oppositely to the sun gear 45 and is being driven through the D planetary. With lever 60 in its uppermost positron (FIG. 1), the D reactor rotates in the same direcmen as sun 15 .and hence SD2 is maximum=600 r.p.m. Therefore, the maximum speed of the reactor 41 of the B planetary in rotating oppositely to sun 45 is:

of 8B2 with lever 60 central.

3 B 5Sdm(500) 500=375 r.p.m.

of SB? with sun fixed but B reactor rotating in the same direction as sun 45 if sun were released.

60 B 5861 =375 r.p.m.

of 8B2 with sun fixed but B reactor rotating oppositely to sun 45 1f sun were released.

B rds=SB2 with reactor of B planetary rotating in the same direction as sun 45.

SB2=375+375=750 r.p.m. (max.) with lever 60 in its lower position.

B ros=SB2 with reactor of B planetary rotating oppositely to sun 45.

SB2=375-375=0 r.p.m. (min) with lever 60 in its upper position.

B planetary (2100 r.p.m. of B1) Referring to FIG. 12, the B reactor 41 is rotating in the same direction as sun 45 and is driven through the D planetary. With lever 60 in its lower position, the reactor of the D planetary rotates oppositely to sun 15 and hence SD2 is minimum or 300 r.p.m. However, during phase 12, the lever 60 is moved to its upper position where the reactor and sun of D planetary rotate in the same direction and SD2 is maximum 600 r.p.m. Therefore, the maximum speed of B reactor 41 in rotating in the same direction as sun 45 is:

Referring to FIG. 9, the B reactor 41 is rotating oppositely to sun 45 and is driven through the D planetary. With lever 60 in its upper position, the reactor of the D planetary rotates in the same direction as the sun 15 and SD2 is maximum 600 r.p.m. Therefore, the maximum speed of the reactor 41 of the planetary in rotating oppositely to sun 45 is:

SBR SD2(max.) X

of SBZ with lever 60 central.

B sd- (500) 300)375 'oo+20 *4 P of SE2 with sun fixed but B reactor rotating in the same direction as sun 45 if sun were released.

= 500 r.p.m.

B rds=SB2 with reactor of B planetary rotating in sam direction as sun 45.

SB2=525+375=900 r.p.m. (max) with lever 60 in its lower position.

B r0o=SB2 with reactor of B planetary rotating oppositely to sun 45.

SB2=525225=300 r.p.m. (max) with lever 60 in its upper position.

The foregoing may be summarized as follows:

SUMMARY SD2 Shait, r.p.m. Rotation of D Reactor Lover 60 300 (more) Opposite to sun 15 Lower sition. 450 (base speed) 0 Contra position. 002 (main) Direction oi sun 15 Upper position.

. 8C2 Shaft, r.p.m. Rotation 0! C Reactor Lever 60 Direction oi sun 14 Lower position. 0 Centre position. Opposite to sun 14 Upper position.

8A2 Sheitnpm. 'Rotation oi A Reactor Lover 60 900 (mex.)..-....... Direction 0! sun 34. Lower position. 525 (base speed). 0 Centre position. 300 (max.)...,... Opposite to sun 3 Upper position.

8B2 Sitai t r.p.m. Rotation oi B Reactor Lover '60 750 (max) Same direction as sun 45- Lower osition. 376 (base speed) 0 Centre position. 0 Opposite to sun 45 Upper position.

. 8B2 shat? r.p.m. Rotation of B Reactor Lever 60 900 (mex.).. Lower ition. 525 base speed Centrn position. 300 imax.).. Opposite to sun 45. Upper position.

In the following charts and in the drawings, the lever 60 will be shown in an upper, intermediate and lower position. The letters beside it will indicate the direction of SBZ with sun fixed but B reactor rotating oppositely to sun 45 if sun were released.

of rotation of the reactors of the planetaries D or C under consideration. Thus, Drds=p reactor rotating in the direction of its sun; and Dr0s=D reactor rotating opposite to its sun, and so on.

HDZIDDI+721 T6XSDR, where Dbl-rhea speed at n planetary.

sea-iamfi xsan. whore Btu-base med cl 8 pllnM-lry.

sri-sm (3-1); sen-om (g); sariam BBB-(column o).

SHAFT TORQUE, IN. LBS.

m (column 12).

TDR= linux (column 12 'r R. .r. srmr'r HORSEPOWER H.P.='2 [T'-D-L Lever PA= Unit 60 PEI PR2 PBR= PBl PD2 Pm PDR PBl-PBR 56 P05. PD2 (BR opposite sun45) A PDI PDR 1 Drdsl o o 29.9 29.9 29.9 22.4 7.4 o

PDl 2 7.45 7.45 22.4 29.9 22.5 22.4

PDl-PDR Dros3 14.9 14.9 14.9 29.9 144; 22.4 7.4 14.9

From the above chart it is evident that as the hand derived as follows, assuming a diametral pitch of 8 for lever 60 (FIG. 1) moves from its solid line position (l) the planetary gears: to its dotted line position (3), the B reactor 41 rotates from 550 r.p.m. to 250 rpm, with the B reactor 41 rotating in a direction opposite to that of the sun gear 45. Furthermore, the speed of shaft E1 varies from 0 to 50 r.p.m. as lever 60 is moved from position 1 to position 3. Since the output torque of 18,800 inch pounds is constant from zero r.p.m. of shaft E1 to 134 r.p.m., the torque for the three positions of lever 60 of FIG. 1 is 18,800 inch pounds. The torque The torque on the B reactor=TBR= iTB2 which is derived as follows:

From a study of the accompanying Chart 1 and assuming 100% efficiency, it is evident that the power input at A1 is equal to the power output at E1 and is the algebraic sum of the power passing through the B planetary,

namely, the algebraic sum of the power in B1 that is transmitted thereto through gear train 10, '11, -53, 54, 51, 50, and the power at the B reactor 41 which is made up from the power through the sun and the reactor 24 of the D planetary, and which latter is transmitted to the B reactor 41 through the gear train 26, 25, 38, 39 and 40. Since the B reactor 41 is rotating oppositely to the sun 45, the power at the B reactor 41 subtracts from the power in shaft B1 and PA=PBl-PBR.

Accordingly, in moving lever 60 from its number 1 position to its number 3 position, the speed of E1 varies from 0 to 50 rpm. with the power varying from 0 to 14.9 HP. At 50 rpm. of the E1 shafit, it is to be noted that the speed of shafts L1 and C3 is 500 rpm. and the speed of shaft C2=Crds=Cbs+Csd=500 r.p.m. (column 7).

Accordingly, the clutch M (FIG. 2) may be engaged and clutch N disengaged since shaft C2 and gear are both rotating at 500 r.p.m. This causes the power to flow through the transmission in the same manner as it :did in FIG. 1, except that the power to the B reactor 41 is now transmitted through the C planetary instead of the D planetary, and through the gear train 25, 38, 39 and 40. Since the B reactor is still rotating oppositely to the sun 45, the power at the B reactor subtracts from the power at B1.

As will be explained later, the control for the transmission will cause the speeds of shaft C2 and C3 to be slightly non-synchronous at the speed at which clutch M is to be engaged in order to prevent tooth-on-tooth contact of the positive tooth clutches. In order to avoid rendering this portion of the description more complex,

, it will refer to an exact synchronous speed at which the various clutches are shifted.

Chart 2 ILRM. POWER LINE STAGE 2 40 ILP.

Clutch Lever 8C2 SL1 8BR BB2 SE1 SE1 801 EUR 1 Crds. 500 500 260 187. 5 1,500 700 388.8

LMxs 2 250 250 125 281.25 15 1,500 700 0 3 CroS. 0 0 0 375 100 1,500 700 388. 8

SB2=Bba+ XSBR where Btu-base speed 0113 planetary. SC2= Cba+ g $(SCR, where Cba=bnsc speed 01 C planetary. SL1=SC2X SC1=SAXZ;; SCR=(oolumn 7).

a a a a a .SBR=SL1X (opposite sun 45), SE1-SAX X X X l2 SE1=SB2?(5.

SHAFT TORQUE, IN. LBS.

Lever 'IEl 'IBZ 'IBR T31 T02 T01 TCR 60 P08.

TB2=TE1X1; TBR= T82 (column 11 Tin- T82 (column 11 TC2=TBRX w V T01=TC2X TCR= Tax? (similar to derivation for D reactor, column 12).

. 'IXR.P.M. SHAFT HORSEPOWER ELF-W Lever PA= Unit 60 PEI PR2 PBR- P31 P02 P01 PCR Pin-PER 66 Poe. P02 (BRop lte sun PC1+PCR 8 Croc 1 14.9 14.9 14.9 29.8 14.9 7.45 7.46 14.9

. PCI 2 2 22.4 22.4 7.46 29.8 7.45 7.45 0 22.4

- POI-POE 1 Crdll 29.8 29.9 0 29.8 0 7.46 7.45 29.8

From an inspection of Chart 2 and FIG. 2, it is evident that by moving lever 60 from its number 1 solid Chart 3 R.P.M. POWER LINE STAGE 3 40 11.1.

Clutch Lever 8C2 8C3 SBR SE2 SE1 S131 801 SCR 1 Croso o o '315 100 1, 500 700 388. s

r 250 250 125 LMRSO 468 75 125 1, 500 700 2A 340 340 170 603 134 1, 500 700 139 3 Crds- 500 500 250 562. 150 I, 500 700 388. 8

ll 1 SB2=Bbs+ XSBR, where Bbs=base speed of B planetary.

2 SC2= Carl- 1 XSCR, where Cba=buse speed of C planetary. sca=sc2; sBR=sca (direction of sun sE1=sB2x:.

21 63 21 25 21 SB1 =SAX X- X X SCI=SAX SCR (column 7).

SHAFT TORQUE, IN. LBS.

Lever TE]. TB2 TBR TB! 'IC2 ICl 'ICR 60 P05.

1 Cros- 18, 800 5, 000 3, 750 i, 250 1, 876 670 1, 205 2 18, 800 5,000 I 3, 750 1, 250 l, 875 670 l, 205

3 Crds. 16, 800 4, 475 3, 355 l, 120 1, 675 600 1,075

12 3 1 TB2=TElX TB T82 (column 11); T131= T132 (column 11). T02: TBRXg.

T01= TC'2X- TCR= 702x? (similar to derlvntlon for D reactor, column 12).

'IXR.P.M. SHAFT H0 RSEPOWER II.P.-

Lover PA 1 PEI P132 PBR= PBI IC2 PCl lCR IBl-HBR P08. PCZ (ll R=dlrcctlon sun 45) PCl-PCR 1 Cros 1 29. 8 29. 8 0 20. 8 7. 46 7. 45 20. 8

: 1 o1+rc a 2A 10. 2 29. 8 .2 7. 45 2.75 40 3 PCl-l-PC R Crds 8 4O 13. 25 25. 7 6.65 6. G5 40 line position hack to its number 3 dotted line position, the speed of E1 varies from 50 rpm. to 100 r.p.m., and the power of E1 varies from 14.9 HP. to 29.8 Hi.

When the lever 60 is in its number 3 position (FIG. 2), the speed of the B reactor 41 is zero, as is the speed of the C2 and C3 shaft-s. Accordingly, clutch -R may he engaged and clutch X disengaged. This sets up the transmission for phase 3 as shown in FIG. 3. The power now flows to the B reactor 41 through the C planetary but through the gear train 49 and 40. Since the L1 shaft and gears 38 and 39 are not in this gear train, the B reactor 40 now rotates in the same direction as sun 45 and, therefore, its power adds to that of B1. As previously described, reactor 41 has stopped at the end of phase 2, so that as lever 60 is now moved during phase Fromgan inspection of Chart 3, it is evident that the speed of E1 increases from rpm. to rpm, and the power output varies from 29.8 HP. to 40 HP. The output horsepower of reactor 40 is achieved when lever 60 is at its number 2A position when shaft E1=134 r.p.rn. No further increase in power can be delivered [from shaft E1 since only 40 HP. is supplied to shaft A1. Therefore, as the speed of E1 increases albove 134 r.p.m., the available torque begins to fall oif.

During phase 3 (FIG. 3), the power flowing through the B planetary is made up of the algebraic sum of the power in B1 and that of the B reactor 41, which latter is made up of the power from the C planetary. The power'from the C planetary is the algebraic sum of the powerfrom shaft C1 and from C reactor 20. Since C 3 from its number 1 position to its number 3 position, 75 reactor 20 is rotating in the opposite direction from sun 

1. IN A LATHE, A WORK-SUPPORTING TABLE; A TOOL HEAD ADAPTED TO BE MOVED ACROSS SAID TABLE TO POINTS ON EITHER SIDE OF THE AXIS OF ROTATION OF SAID TABLE FOR REMOVING METAL FROM WORK FIXED TO SAID TABLE; MEANS CONNECTED TO SAID TOOL HEAD FOR MOVING IT; A VARIABLE SPEED TRANSMISSION FOR ROTATING SAID WORK-SUPPORTING TABLE AND FOR DRIVING SAID MEANS FOR MOVING SAID TOOL HEAD; MEANS FOR VARYING THE SPEED OF SAID TRANSMISSION; BALANCED ELECTRICAL IMPEDANCE MEANS FOR CONTROLLING THE OUTPUT SPEED OF ROTATION OF SAID TRANSMISSION INCLUDING A FIRST ELEMENT ADAPTED TO BE MOVED IN PROPORTION TO THE MOVEMENT OF SAID TOOL HEAD AND A SECOND ELEMENT CONNECTED TO SAID TRANSMISSION SPEED VARYING MEANS AND MOVABLE IN PROPORTION TO THE VARIATION IN SPEED OF SAID WORK-SUPPORTING TABLE; CAM MEANS CONNECTED TO THE MEANS THAT MOVES SAID TOOL HEAD FOR MOVING SAID FIRST ELEMENT SO THAT A SUBSTANTIALLY CONSTANT CUTTING SPEED OF SAID WORK CAN BE MAINTAINED AS SAID TOOL HEAD MOVES TO DIFFERENT RADII OF SAID WORK; AND MEANS FOR ADJUSTING SAID CAM MEANS RELATIVE TO SAID FIRST ELEMENT, WHEREBY A PREDETERMINED SUBSTANTIALLY CONSTANT CUTTING SPEED CAN BE MAINTAINED AS SAID TOOL HEAD MOVES TO DIFFERENT RADII OF SAID WORK. 